An aroma of decaying apples, later identified as acetone, was noted by a physician, John Rollo, in 1796 in a patient with severe diabetes. Various quantitative methods for detecting presence or absence of acetone were subsequently developed for purposes of detecting diabetes in a patient. These methods included gas chromatography with flame ionization detection. Presence of other substances, such as NO, H2O2, carbonyl sulfide, dimethyl sulfide, pentane, methane, isoprene and/or isopentane have been noted in a patient's breath, in association with other diseases. The detection methods for a particular biomarker are often complex and time consuming, and presence of a given biomarker (referred to herein as a “specified component”) is often consistent with presence of any of several diseases. For example, presence of NO in a patient's breath may indicate that the patent has one or more of asthma, COPD, cystic fibrosis and/or lung cancer, among other maladies.
What is needed is a method that is relatively simple, requires no more than about 60 sec to complete, is quantitatively specific for identification of a particular disease or medical condition, and uses a minimum number of chemical or physical tests that can be performed, simultaneously or sequentially, to indicate presence of one disease or medical condition, where possible. Preferably, the system should permit detection of presence of a given biomarker, associated with an identified disease or medical condition, down to a few parts per billion (ppb) concentration.